But all of Europe was developing 4th gen fighter despite F-22. But this time France would be the only one "behind" with Sweden.
You are 100% wrong.
Turkey KAAN
Korea KF-21
India AMCA
Sweden Flygsystem 2020
Russia Su-57
Russia Su-75
These are all 5th gen fighters under development. France would not be the "behind'. France could actually be the first country to make an aircraft that beats the F-35 in all areas. France already has excellent avionics and engine technology in the Rafale. All of the other countries on the above list either lack indigenous engines, avionics or both.
I would also avoid using the 5th gen and 6th gen labels. The main key difference between 4th and 5th gen was stealth. Some 4.5 gens had supercruise and sensor fusion so these are not 5th gen exclusive.
What is 6th gen?
A bit more speed
A bit more range
A bit more stealth
A bit more electrical generation
A bit more powerful radar
A bit more sensor fusion
Maybe lasers.
A 5th gen fighter design can get a mid life refresh with a more advanced adaptive engine, radar and stealth coating. Then technically it gains everything on this list. It becomes 6th gen.
It seems people want to define 6th gen as having Mach 2 supercruise and 1,000nm combat radius. This can only be achieved by 100,000+lb MTOW fighters.The F-22, Su-57 and J-20 are heavy class. So it makes sense to call the 6th gen designs super heavy.
I doubt a true 6th gen fighter design can fit on a French carrier. I can see it getting the 5.5 gen label as the size will limit how far it can exceed the F-35 benchmark. The smaller Gripen for example was always behind the Rafale and Eurofighter due to the lower range and smaller radar. It was hard to call the original Gripen a 4.5th gen fighter.
The public will not know if a design has 5th or 6th gen levels of stealth which makes this even harder.
I could see a super heavy weight 5th gen fighter getting incorrectly called 6th gen because the large size is associated with being 6th gen. The UK Tempest fighter could easily fall into this category depending on how high they set the performance targets. The Chinese 3 engine fighter might be a perfect example of this. It could be another foxbat moment.
We will eventually have people saying 5.25 gen and 5.75 gen depending how many of the 6th gen requirements are achieved. This will be incredibly annoying for some people as it is entirely open to interpretation.